A method for separating amphoteric metals in waste circuit boards

A technology for waste circuit boards and amphoteric metals, applied in chemical instruments and methods, improvement of process efficiency, inorganic chemistry, etc., can solve the problems of less research on the separation and recovery of amphoteric metals, high requirements for working environment, poor selectivity of raw materials, etc., to achieve Efficient and clean production, less corrosive equipment, and selective separation of metals

Active Publication Date: 2017-05-03
CENT SOUTH UNIV
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method has problems such as poor selectivity of raw materials, low metal recovery rate, and high requirements for the working environment in the process of recycling valuable metals in circuit boards.
[0004] At present, there are many methods for recycling valuable metals in waste circuit boards at home and abroad, but a lot of research has been done on copper and precious metals, and there are few researches on the separation and recovery of amphoteric metals.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for separating amphoteric metals in waste circuit boards
  • A method for separating amphoteric metals in waste circuit boards
  • A method for separating amphoteric metals in waste circuit boards

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] A method for separating amphoteric metals in waste circuit boards of the present invention, its process flow chart is as follows figure 1 shown, including the following steps:

[0038] (1) Low-alkali leaching: Take 500g of waste circuit board polymetallic powder, add NaOH solution with a concentration of 2mol / L for leaching (the liquid-solid ratio of NaOH solution to polymetallic powder is 10:1), and the leaching temperature is 50°C Stirring and leaching for 30 minutes, wherein the stirring power is 300r / min, and filtering after stirring and leaching to obtain low-alkali leaching residue and low-alkali leaching solution. Copper, lead, tin and precious metals enter the low-alkali leaching slag (the XRD pattern is shown in image 3shown); aluminum and zinc enter the low-alkali leaching solution, and the leaching rates are 98.31% and 97.14% respectively. Add NaOH solution to the low-alkali leaching solution and return to the leaching step for recycling. After the valuabl...

Embodiment 2

[0041] A method for separating amphoteric metals in waste circuit boards of the present invention, its process flow chart is as follows figure 1 shown, including the following steps:

[0042] (1) Low-alkali leaching: Take 500g of waste circuit board polymetallic powder, add NaOH solution with a concentration of 1mol / L for leaching (the liquid-solid ratio of NaOH solution to polymetallic powder is 20:1), and the leaching temperature is 60°C. Stirring and leaching for 90 minutes, wherein the stirring power is 300r / min, and filtering after stirring and leaching to obtain low-alkali leaching residue and low-alkali leaching solution. Copper, lead, tin and precious metals enter the low-alkali leaching slag; aluminum and zinc enter the low-alkali leaching solution, and the leaching rates are 92.36% and 91.52%, respectively. Add NaOH solution to the low-alkali leaching solution and return to the leaching step for recycling. After the valuable metals are enriched to a certain extent, ...

Embodiment 3

[0045] A method for separating amphoteric metals in waste circuit boards of the present invention, its process flow chart is as follows figure 1 shown, including the following steps:

[0046] (1) Low-alkali leaching: Take 500g of waste circuit board polymetallic powder, add KOH solution with a concentration of 2mol / L for leaching (the liquid-solid ratio of KOH solution to polymetallic powder is 8:1), and the leaching temperature is 30°C. Stirring and leaching for 60 minutes, wherein the stirring power is 300r / min, and filtering after stirring and leaching to obtain low-alkali leaching residue and low-alkali leaching solution. Copper, lead, tin and precious metals enter the low-alkali leaching slag; aluminum and zinc enter the low-alkali leaching solution, and the leaching rates are 95.62% and 92.31%, respectively. Add KOH solution to the low-alkali leaching solution and return to the leaching step for recycling. After the valuable metals are enriched to a certain extent, alum...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method for separating amphoteric metal in waste circuit boards. The method includes the steps of firstly, adding multi-metal powder of the waste circuit boards into an alkali solution with the concentration being 0.5-2mol / L, stirring under 30-80 DEG C for leaching, and filtering to obtain low-alkali leaching residues and low-alkali leachate containing aluminum and zinc; secondly, adding the low-alkali leaching residues into an alkali solution with the concentration being 1-4mol / L, adding oxidizing agent with the amount being 1-10 times of the theoretical amount at the same time, stirring under 30-80 DEG C for leaching, and filtering to obtain high-alkali leaching residues and high-alkali leachate containing lead and tin. The method has the advantages that step-by-step alkali dissolution is performed on the amphoteric metal in the waste circuit boards, the metal is separated selectively, the leachate is simple in component, few in impurity and easy to separate, the recycled product is high in puerility and low in equipment corrosion, production cost is lowered, and production efficiency is increased.

Description

technical field [0001] The invention belongs to the technical field of recycling of waste resources, and in particular relates to a method for separating amphoteric metals in waste circuit boards by using a step alkali solution. Background technique [0002] In recent years, with the acceleration of the replacement of electronic products, my country has produced a large amount of electronic waste. These electronic wastes are complex in composition and contain a lot of toxic chemicals. If they are directly landfilled, the heavy metals in them will pollute the soil and water resources. If they are directly incinerated, the organic substances in them will release substances such as dioxins and furans after incineration. and other harmful gases, causing harm to the natural environment and human body. In addition, electronic waste contains a large amount of recyclable metals, such as aluminum, copper, lead, zinc, precious metals (gold, silver), and platinum group metals. These m...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): C22B7/00C22B11/00C22B13/00C22B15/00C22B19/30C22B19/20C22B21/00C22B25/06C01G19/00
CPCC01G19/00C22B7/008C22B11/046C22B13/045C22B15/0065C22B19/24C22B21/0023C22B25/06Y02P10/20
Inventor 田庆华郭学益江晓健李栋
Owner CENT SOUTH UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap